The body is thrown vertically upwards from a height of 5 m at a speed of 30 m / s.

The body is thrown vertically upwards from a height of 5 m at a speed of 30 m / s. What speed and at what height will the body have in 6 s?

h = 5 meters – the height from which the body was thrown;

V0 = 30 m / s – the speed with which the body was thrown;

t = 6 seconds.

g = 10 m / s ^ 2 – acceleration of gravity.

It is required to find the height of the body H (meters) and the speed V (m / s) in time t.

At the maximum point of height, the body’s velocity will be zero. Therefore, we will find the time after which the body will reach the maximum point:

t = V0 / g = 30/10 = 3 seconds.

During this time, the body will rise to a height:

h1 = h + V0 * t – g * t ^ 2/2 = 5 + 30 * 3 – 5 * 9 = 5 + 90 – 45 = 50 meters.

For the remaining time of 3 seconds, the body will descend to a height:

H = h1 – g * 3 ^ 2/2 = 50 – 10 * 9/2 = 50 – 5 * 9 = 50 – 45 = 5 meters.

Moreover, its speed will be equal to:

V = g * 3 = 10 * 3 = 30 m / s.

Answer: after 6 seconds the body will be at a height of 5 meters and have a speed of 30 m / s.